The synthesis, structure and photophysical properties of a series of highly emissive europium complexes is reported. Certain complexes enter mammalian cells by

Citation for published item:ouli¡ eD wrine nd vtzkoD pr¡ ed¡ eri nd fourrierD immnuel nd lideD irginie nd futlerD tephen tF nd lD oert nd ltonD tmes F nd fldekD trie vF nd ve quenniD foris nd endrudD ghntl nd wierD turrin wF nd vmrqueD vurent nd rkerD hvid nd wuryD ylivier @PHIRA 9gomprtive nlysis of onjugted lkynyl hromophoreEtrizylononne lignds for sensitized emission of europium nd teriumF9D ghemistry X iuropen journlFD PH @PVAF VTQT EVTRTF Further information on publisher's website: his is the epted version of the following rtileX ouli¡ eD wFD vtzkoD pFD fourrierD iFD lideD FD futlerD F tFD lD FD ltonD tF FD fldekD F vFD vequenniD fFD endrudD gFD wierD tF wFD vmrqueD vFD rkerD hF nd wuryD yF @PHIRAD gomprtive enlysis of gonjugted elkynyl ghromophore!rizylononne vignds for ensitized imission of iuropium nd eriumF ghemistry E iuropen tournlD PH @PVAX VTQTEVTRTD whih hs een pulished in (nl form t httpXGGdxFdoiForgGIHFIHHPGhemFPHIRHPRISF his rtile my e used for nonEommeril purposes in ordne with ileyEgr erms nd gonditions for selfErhivingF Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract. An extensive series of europium and terbium complexes is described based on the same functionalised tri-azacyclononane carboxylate or phosphinate macrocyclic ligand. The influence of the anionic group, i.e. carboxylate, methyl or phenyl phosphinate, on the photophysical properties is studied and rationalised on the basis of DFT calculated structures. The nature, number and position of aryl electron-donating or withdrawing substituents have been varied systematically within the same phenylethynyl scaffold in order to optimize the brightness of the related europium complexes and investigate their two-photon absorption properties. Finally, the europium complexes were examined in cell imaging applications, whilst selected terbium derivatives were studied as potential oxygen sensors.2 Introduction.

Publisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. FRS (1932FRS ( -2014 The development of the brightest luminescent europium(III) complexes is traced, including analysis of the C 3 -symmetric core complex based on a functionalized triazacyclononane and identification of the most suitable strongly absorbing chromophore. Strategies for the synthesis of the complexes, including enantiopure analogues, are outlined and opportunities for applications in time-resolved microscopy and spectral imaging emphasised. Practicable examples are introduced, including selective organelle staining for cellular optical imaging at 65 nm resolution and the development of new bioassays using time-resolved FRET methods.

Nonadentate ligands based on triazacyclononane incorporating pyridyl-2-phosphinate groups form an isostructural series of complexes with Ln ions in the solid state and in solution. The Ln ion is effectively shielded from the solvent environment. Crystal structures reveal a rigid C(3)-symmetric tricapped trigonal-prismatic coordination geometry that is maintained in solution for the methyl and phenylphosphinate series, as shown by multinuclear NMR analysis. Variable-temperature measurements of the field dependence of the water proton relaxivity in gadolinium complexes indicate that these systems exclude solvent from the primary coordination environment and minimize the second sphere of solvation. The electronic relaxation time for the gadolinium methylphosphinate complex has been estimated to be 550 (±150) ps by EPR and NMR methods, compared to values of around 0.30-0.05 ps for the terbium-ytterbium series, deduced by analyzing the field dependence (4.7-16.5 T) of the (31)P NMR longitudinal relaxation times. Values are compared with analogous azacarboxylate ligand complexes, supporting a key role for donor atom polarizability in determining the electronic relaxation. Spectral emission behavior in solution of samarium, europium, terbium, and dysprosium complexes is compared, and the resolved RRR-Λ and SSS-Δ complexes show strong circularly polarized luminescence. The molecular quadratic hyperpolarizability 〈β(HLS)〉 has been measured in solution using hyper-Raleigh light-scattering methods, for the whole series of lanthanide complexes of one ligand. The values of 〈β(HLS)〉 reach a maximum around the center of the series and are not simply dependent on the number of f electrons, suggesting a dominant contribution from the octupolar rather than the dipolar term.

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A series of five europium(III) complexes has been prepared from heptadentate N5O2 ligands that possess a brightness of more than 10 mM(-1) cm(-1) in water, following excitation over the range λ=330-355 nm. Binding of several oxy anions has been assessed by emission spectral titrimetric analysis, with the binding of simple carboxylates, lactate and citrate involving a common ligation mode following displacement of the coordinated water. Selectivity for bicarbonate allows the rapid determination of this anion in human serum, with K(d)=37 mM (295 K). The complexes are internalised quickly into mammalian cells and exhibit a mitochondrial localisation at early time points, migrating after a few hours to reveal a predominant lysosomal distribution. Herein, we report the synthesis and complexation behaviour of strongly emissive europium (III) complexes that bind oxy-anions in aqueous media with an affinity and selectivity profile that is distinctively different from previously studied systems.

Lanthanide complexes of a pyridylphenylphosphinate ligand based on triazacyclononane form an isostructural series. The C(3)-symmetric Δ and Λ complexes of Eu and Tb are strongly emissive and can be resolved by chiral HPLC; the absolute configuration of each complex has been assigned using CD and CPL measurements.

The emission intensity of a monocationic Tb or Eu(III) complex of a bis(1-azaxanthone) ligand is enhanced in the presence of serum albumin; the lanthanide complex stains dividing cells, allowing visualisation of mitotic chromosomes.